ABSTRACT Rhodococcus fascians is a gram-positive phytopathogen that infects a wide range of plant species. The actinomycete induces the formation of neoplastic growths, termed leafy galls, that consist of a gall body covered by small shoots of which the outgrowth is arrested due to an extreme form of apical dominance. In our previous work, we demonstrated that in the developing gall, auxin drives the transdifferentiation of parenchyma cells into vascular elements. In this work, with the use of transgenic Arabidopsis thaliana plants carrying molecular reporters for cell division (pCYCB1;1:GUS) and meristematic activity (pSTM:GUS), we analyzed the fate of cells within the leafy gall. Our results indicate that the size of the gall body is determined by ongoing mitotic cell divisions as illustrated by strong CYCB1;1 expression combined with the de novo formation of new meristematic areas triggered by STM expression. The shoot meristems that develop in the peripheral parts of the gall are originating from high ectopic STM expression. Altogether the presented data provide further insight into the cellular events that accompany the development of leafy galls in response to R. fascians infection.

中文翻译：

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拟南芥上的筋膜红球菌诱导的肿瘤组织中持续的 CYCLINB1;1 和 STM 表达是叶瘿结构持续存在的基础

摘要红球菌 fascians 是一种革兰氏阳性植物病原体，可感染多种植物。放线菌诱导肿瘤性生长的形成，称为多叶瘿，其由被小芽覆盖的瘿体组成，由于顶端优势的极端形式，小芽的生长被阻止。在我们之前的工作中，我们证明了在发育中的胆囊中，生长素驱动薄壁细胞转分化为血管成分。在这项工作中，我们使用携带分子报告基因进行细胞分裂 (pCYCB1;1:GUS) 和分生组织活动 (pSTM:GUS) 的转基因拟南芥植物，分析了叶瘿内细胞的命运。我们的结果表明，如强 CYCB1 所示，胆囊体的大小是由正在进行的有丝分裂细胞分裂决定的。1 表达与由 STM 表达触发的新分生组织区域的从头形成相结合。在胆的外围部分发育的芽分生组织源自高异位 STM 表达。总而言之，所提供的数据提供了对伴随 R. fascians 感染的叶瘿发育的细胞事件的进一步了解。